Hinging means for oven heating element



Jan. 3, 1967 A..J. MACAULAY 7 3,296,417

HINGING MEANS FOR OVEN HEATING ELEMENT 7 Filed July 31, 1964 INVENTOR. ANGUS I MAcAuL/w ms ATTORNEY United States Patent 3,296,417 HINGING MEANS FOR OVEN HEATING ELEMENT Angus J. Macaulay, Louisville, Ky, assignor to General Electric Company, a corporation of New York Filed July 31, 1964, Ser. No. 386,563 4 Claims. (Cl. 219-404) The principal object of the present invention is to provide a hinging means for a metal sheathed electric heating element, and particularly for the lower heating element or bake unit of an electric oven for use in the home.

Up until recent years the lower heating element or bake unit in an electric oven had been supported adjacent the bottom wall of the oven, and plugged into an electrical connector block mounted in the back wall of the oven liner. The reason for having this type of removable connection was to facilitate the ease of withdrawing the bake unit from the oven so that food soil and grease spatter that normally accumulates on the bottom wall of the oven liner may be scrubbed clean without interference from the bake unit. This removal of the bake unit was a source of some'annoyance to the housewife because of the difficulty experienced in positioning the bake unit back into the connector block.

In recentyears the connector block design has been largely eliminated in favor of a pivotal mounting bracket for the bake unit so that the unit may be raised and held in an inclined position and the food soil and grease spatter may be cleaned out from underneath without disconnecting the bake unit.

The principal object of the present invention is to provide a hinging system for a metal sheathed electric heating element having a simplified pivot means that facilitates the ease of assembly of the various parts of the system.

A further object of the present invention is to provide a hinging means of the class described with a loosely fitted pivotal means between a heating element, a hinge plate and its mounting plate, wherein the interference of the heating element with the mounting plate serves as a limit means to prevent the disassembly of the hinge plate from the mounting plate.

A still further object of the present invention of the class described is to provide an improved detent means cooperating with the hinge plate for holding the heating element in its raised position.

The present invention, in accordance with one form thereof, is embodied in a metal sheathed electric heating element for pivotal connection to a supporting wall, such as the back wall of an oven enclosure. A pivotal mounting means is provided and it comprises a mounting plate that is adapted to be secured over an aperture in the wall. This mounting plate is provided with window means, and a hinge plate is positioned over the window means and is adapted for a pivotal support from the mounting plate. A parallel pair of spaced tabs is formed adjacent the two sides of the mounting plate and extending rearwardly thereof Where each tab is formed with a slotted opening having a restricted entrance. Moreover, the hinge plate has oppositely extending ears adapted to be loosely confined Within the slotted tabs for pivotal movement therein. A metal sheathed electric resistance heating element of looped configuration has terminal end portions that are adapted to be made integral with the hinge plate,'where the heating element serves as a means to limit the pivotal action of the hinge plate thus preventing the ears of the hinge plate from becoming disengaged from the slotted tabs.

My invention will be better understood from the follow ing description taken in conjunction with the accompanythe present invention;

FIGURE 2 is a front elevational view on an enlarged scale of the mounting bracket of the hinged connection for the oven bake unit illustrated in FIGURE 1;

FIGURE 3 is a cross-sectional plan view of the mounting bracket of FIGURE 2 taken on the line 33 of FIG- FIGURE 4 is a cross-sectional side elevational view of the mounting bracket taken on the line 44 of FIG- URE 2 and showing the hinge plate pivoted to its rea -v most position so that the heating element is held in an inclined raised position for cleaning underneath;

FIGURE 5 is a cross-sectional side elevational view similar to that of FIGURE-4 but taken on the line 55 of FIGURE 2 and showing the hinge plate in its normal vertical or closed position.

Turning now to aconsideration of the drawings, and in particular to FIGURE 1, there is shown for illustrative purposes an electric oven 10 formed by a box-like oven liner 11 and a front-opening drop door 12 which together define an oven cavity 13. A suitable thermal insulation such as fiberglass 14 is installed around the outside of the oven liner as well as being packed within the oven door 12. Surrounding the insulation 14 is the oven body 15 or cabinet structure defining whether the oven is a builtin wall oven or the oven of a free-standing range, as the case may be. There is a slight difference in structure at the back of the oven where ther is an insulation guard or panel 16 that confines the insulation and in cooperation with a back wall 18 of the oven cabinet establishes a wiring compartment 17 so that the necessary electrical connections (not shown) can be made in the wiring compartment 17 while being properly shieldedfor safety reasons.

A standard electric oven is usually provided with two heating elements; namely, a lower heating element or bake unit 20 that is slightly spaced above the bottom Wall of the oven cavity, and an upper broil unit (not shown) positioned slightly below the top wall of the oven liner. The present invention is primarily concerned with a mounting bracket 21 located adjacent the terminal portion of the bake unit 20 for connection and support from a back wall 22 of the oven liner. The oven bake unit 20 is a metal sheathed electric resistance heating element of standard construction having a helical resistance wire extending through the center of a tubular sheath, where the wire is insulated from the sheath by a suitable heat conducting electrically insulating material such as a highly compacted granular magnesium oxide. The ends of the resistance wire are attached to a relatively large diameter terminal pin such as pin 25 at the terminal end portions shown in FIGURE 3 and a suitable seal (not shown) is installed in the end of the sheath to plug the opening and prevent any moisture from entering the insulation as Well as to prevent any other type of damage to the insulation. Such a heating element is formed in a loop of serpentine configuration as is best illustrated in FIGURE 1 so as to supply heat energy in the most efficient manner throughout the oven cavity for optimum baking results. Suitable clip members 26 are fastened to the sheath and underlie the element to serve as supporting feet to space the bake unit 20 above the bottom wall of the oven liner so as not to overheat the porcelain enamel finish on the oven liner 11.

The back wall 22 of the oven liner is provided with a generally rectangular aperture over which the mounting bracket 21 of the present invention is to be fastened so that the terminals of the bake unit extend therethrough for making an electrical connection outside of the oven cavity. Looking at the front elevational view of FIGURE 2 the mounting bracket 21 includes a mounting plate 28 of generally rectangular shape which is adapted to be fastened over the aperture in the wall 22 as by means of the two fastening screws 29. The mounting plate is provided with window means such as a pair of spaced openings 30 and 31 each of generally square shape that are separated from each other by a central divider 32 which is illustrated as a forward embossment of generally square shape for cooperation with a detent spring 34 of thin sheet metal as seen in FIGURE that is fastened on the back side of the mounting plate 28 by a fastening screw 35. The detent spring 34 is of generally L-shape in side view where one leg 36 of the L extends generally perpendicularly to the plane of the mounting plate 28, while the other leg is vertically disposed within the depression in the back side of the embossment 32. This vertical leg contains a hole for cooperation with the threads of the fastening screw 35.

Next there is a hinge plate 38 as best seen in FIGURE 3 which is assembled to the mounting plate 28 from the rear side thereof to overlie the window openings 30 and 31 as by use of the corresponding portions 39 and 40 respectively which fit snugly into these window openings. Thus, it can be seen that the hinge plate 38 is a generally flat member having two end portions of substantially square shape 39 and 40 forwardly formed to extend into the window openings 30 and 31 so as to lie within the plane of the mounting plate 28. There is an enlarged clearance hole (not shown) in the hinge plate 38 through which the fastening screw 35 extends so as to avoid any interference from the hinge plate, even though the hinge plate is capable of pivotal movement as will be described shortly. Each closure portion 39 and 40 of the hinge plate 38 is provided with a lower apron 41 which overlies the bottom edge of the window 30 or 31 as is best seen in FIGURE 2 so as to prevent any food spatter or grease drippings from leaking through the window openings 30 and 31.

As to the means forsupporting the hinge plate from the mounting plate, reference is first made to FIGURES 3 and 4. The outermost side edge of each window opening 30 and 31 is provided With a tab 43 which extends rearwardly of the mounting plate and in a direction generally parallel with the opposite tab. Looking at FIG- URE 4, each tab 43 is provided with a slotted opening 44 of generally triangular shape having a vertical edge 45, a slightly arched top edge 46 and an inclined edge 47 with a restricted entrance 48 for gaining access to the slotted opening. Going back, to FIGURE 3, each side edge of the hinge plate 38 is provided with a rearwardly offset outwardly extending side car 50 of generally vertical disposition which is adapted to slide end-wise through the restricted opening 48 and to be angled to rest on the lower apex of the slotted opening 44 formed by the vertical edge 45 and the inclined edge 47. Thus, the oppositely extending ears 50 serve as trunnions mounted in journals formed by the slotted openings 44 in the parallel tabs 43. Thus, the hinge plate 38 is capable of pivotal movement between two extreme positions; namely, the vertical or closed position of FIGURE 5 and the backwardly inclined open position of FIGURE 4 which is used for cleaning. It will be noticed that in both positions the horizontal leg 36 of the detent spring 34 resists the hinge plate 38 from changing its position. Only manual force exerted on the hinge plate will enable this plate to move from either of its two extreme positions,

A small grounding spring 53 is clipped on the inner side of one of the tabs 43 of the mounting plate 28 off to one side of the slotted opening 44 as is best seen in FIGURES 3 and 4 for creating at all times a strong rubbing action against the adjacent side edge of the hinge plate 38. This is done to insure the integrity of an electrical ground from the metal sheath of the heating element 28 to the oven liner 11 through the hinge plate 38 and the mounting plate 28.

Means must be provided for mounting the terminal ends of the metal sheathed heating element 20 to the hinge plate 38. This is accomplished by providing a circular opening 49 in each closure portion 39 and 48 of the hinge plate for receiving one of the terminal ends of the bake unit therethrough. As best seen in FIGURE 3, the sides of this opening 49 are drawn rearwardly to form a collar 51 which is acapable of being crimped over the sheath for fastening the heating element permanently to the hinge plate 38.

The heating element serves as a limit means or a looking means when it is raised as in FIGURE 4 where it strikes the top edge of the window openings 30 and 31 in the mounting plate 28 thereby preventing any further rearward movement of the hinge plate 38 from the position shown in FIGURE 4. Thus, it is impossible to disassemble the hinge plate 38 from the mounting plate 28 once the hinge plate is supported from the mounting plate and the terminal ends of the bake unit are made integral with the hinge since it is then no longer possible to angle the mounting ears 50 of the hinge plate through restricted entrance 48 of the slotted openings 44 of the mounting tabs.

Modifications of this invention will occur to those skilled in this art therefore it is to be understood that this invention is not limited to the particular embodiments disclosed but that it is intended to cover all modifications which are within the true spirit and scope of this invention as claimed,

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A sheathed electric heating element for removable connection to an apertured wall of an oven, comprising a mounting plate adapted to be secured over the aperture in the oven wall, said mounting plate containing window means therein, a hinged plate positioned over the window means, and parallel spaced tabs formed on the mounting plate and extending rearwardly thereof, each tab being formed with a slotted opening having a reduced entrance, the hinge plate having oppositely extending ear members formed on the side edges thereof for pivotal support with respect to the said tabs, whereby the hinge plate must be angled to slip the ear members through the reduced entrance of the slotted tabs of the mounting plate for confinement within the said slot, and a pair of openings formed in the hinge plate, and a sheathed electric heating element having terminal ends fixed within the said openings, and detent spring means fastened to the rear surface of the mounting plate and engageable with the top portion of the hinge plate, the electric heating element serving as a limit means for the pivotal action of the hinge plate when it engages an edge of the window means in the mounting plate, said limit means preventing the ear members of the hinge plate from being drawn from the slotted tab.

2. A metal sheathed electric heating element for pivotal connection to a supporting wall, comprising a mounting plate adapted to be secured over an aperture in the wall, said mounting plate having window means therein, a hinge plate positioned over the window means and adapted to be supported from the mounting plate, and a parallel pair of spaced ta'bs formed adjacent the two sides of the mounting plate and extending rearwardly thereof, each tab being formed with a slotted opening having a restricted entrance in the rear edge of the tab, the hinge plate having oppositely extending ears formed on the side edges thereof which are loosely confined within the slotted tabs for pivotal movement therein, and a pair of openings formed in the hinge plate, a metal sheathed electrical resistance heating element of loop-ed configuration having a pair of terminal end portions closely spaced in parallel with each other and extending through the hinge plate openings and made integral therewith.

the heating element serving as a limit means for the pivotal action of the hinge plate when the element engages an edge of the window means in the mounting plate thus preventing the ears of the hinge plate from becoming disengaged from the slotted tabs.

3. A [metal sheathed electric heating element for pivotal connection to a supporting wall, comprising a mounting plate adapted to be secured over an aperture in the wall, said mounting plate having a pair of spaced window openings, a hinge plate positioned over the window opening and adapted to be supported from the mounting plate, and a parallel pair of spaced tabs formed adjacent the two sides of the mounting plate and extending rearwardly thereof, each ta'b being formed with a slotted opening having a restricted entrance in the rear edge thereof, the hinge plate having a pair of rearwardly olfset outwardly extending ears formed in the side edges thereof which are loosely confined within the slotted tabs for pivotal movemerit therein, and a pair of openings formed in the hinge plate, a metal sheathed electric resistance heating element of looped configuration having a pair of terminal ends closely spaced in parallel with each other and extending through the hinge plate openings and made integral therewith, detent spring means fastened to the rear surface of the mounting plate and extending rearwardly thereof to overlie the hinge plate and adapted to hold the hinge plate in its rearwardly hinged position so that the heating element is supported in an upwardly inclined position, the electric heating element serving as a limit means for the pivotal movement of the hinge plate when the element engages an edge of the window openings in the mounting plate, said limit means preventing the ears of the hinge plate from being withdrawn from the slotted tabs.

4. A metal sheathed electric heating element for pivotal connection to a supporting wall as recited in claim 3 wherein the slot in each said tab is of generally inverted triangular configuration with one apex being at the bottom and the other two apexes being at the top, while the restricted entrance to the slot is located at the apex nearest the rear edge of the tab, whereby the mating ear of the hinge plate serves as a trunnion that is adapted to be confined within the lower apex of the slotted tab in the manner of a journal, and spring means fastened on one of the said tabs and pressed at all times into wiping engagement with the adjacent side edge of the hinge plate for grounding purposes.

No references cited.

RICHARD M. WOOD, Primary Examiner.

R. F. STAUBLY, Assistant Examiner. 

1. A SHEATHED ELECTRIC HEATING ELEMENT FOR REMOVABLE CONNECTION TO AN APERTURED WALL OF AN OVEN, COMPRISING A MOUNTING PLATE ADAPTED TO BE SECURED OVER THE APERTURE IN THE OVEN WALL, SAID MOUNTING PLATE CONTAINING WINDOW MEANS THEREIN, A HINGED PLATE POSITIOND OVER THE WINDOW MEANS AND PARALLEL SPACED TABS FORMED ON THE MOUNTING PLATE AND EXTENDING REARWARDLY THEREOF, EACH TAB BEING FORMED WITH A SLOTTED OPENING HAVING A REDUCED ENTRANCE, THE HINGE PLATE HAVING OPPOSITELY EXTENDING EAR MEMBERS FORMED ON THE SIDE EDGES THREOF FOR PIVOTAL SUPPORT WITH RESPECT TO THE SAID TABS, WHEREBY THE HINGE PLATE MUST BE ANGLED TO SLIP THE EAR MEMBERS THROUGH THE REDUCED ENTRANCE OF THE SLOTTED TABS OF THE MOUNTING PLATE FOR CONFINEMENT WITHIN THE SAID SLOT, AND A PAIR OF OPENINGS FORMED IN THE HINGE PLATE, AND A SHEATHED ELECTRIC HEATING ELEMENT HAVING TERMINAL ENDS FIXED WITHIN THE SAID OPENINGS, AND DETENT SPRING MEANS FASTENED TO THE REAR SURFACE OF THE MOUNTING PLATE AND ENGAGEABLE WITH THE TOP PORTION OF THE HINGE PLATE, THE ELECTRIC HEATING ELEMENT SERVING AS A LIMIT MEANS FOR THE PIVOTAL ACTION OF THE HINGE PLATE WHEN IT ENGAGES AN EDGE OF THE WINDOW MEANS IN THE MOUNTING PLATE, SAID LIMIT MEANS PREVENTING THE EAR MEMBERS OF THE HINGE PLATE FROM BEING DRAWN FROM THE SLOTTED TAB. 